en Immunology Immunology Original Research Original Research The association of HLA and disease varies in different populations. We have . studied the association of HLA class I in Iranian psoriatic patients, in order to compare this association with other reports. Fifty-one Iranian patients with psoriasis were HLA typed. The frequency of HLA antigens in patients and patient subgroups, based on clinical patterns, age of onset, family history and provocative factors, were compared with each other and with normal controls. The results indicate that the disease is strongly associated with HLA-Cw6 (chi-square, corrected P-value (Pc)≤0.0009), and negatively associated with Cw3 (Pc≤ 0.00009 and Pc≤ 0.03, respectively). Psoriatic patients with early onset disease and non-pustular psoriasis (NPP) showed a more significant association with HLA-Cw6 (Pc≤ 0.0004 and Pc≤ 0.0003, respectively). There was no statistically significant relationship between the presence of a positive family history and early onset of disease. 37 41 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-460&slc_lang=en&sid=1 HM NIKNAM 20031947532846005448 20031947532846005448 Yes From the Department of Immunology, Pasteur Institute, Tehran P MANSOORI 20031947532846005449 20031947532846005449 No the Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, B NIKBIN 20031947532846005450 20031947532846005450 No the Department of Immunology, Tehran University of Medical Sciences, Tehran M DANESHPAJOUH 20031947532846005451 20031947532846005451 No the Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, A AMIRKHANI 20031947532846005452 20031947532846005452 No the Department of Epidemiology, Pasteur Institute, Tehran, Islamic Republic of Iran. MH ALIMOHAMMADIAN 20031947532846005453 20031947532846005453 No From the Department of Immunology, Pasteur Institute, Tehran